, governator, educators -- the road goes on. >> schwarzenegger is known around the world, but for other authors at the fair, it is not so easy. there are countless titles on display here, and publishers are nervous as they confront the challenge of electronic books. >> we live in the era of digital publishing. there's no question that there are more and more readers who consume literature on their ipads or e-readers. in germany, the numbers are rising as well. >> the book fair has tried to adjust. there are stands offering interactive books. one innovation -- 3d software for textbooks. software companies hope to make education more exciting with their offerings. >> there are some areas where textbooks are no longer so effective. that is where the cyberclassroom can take over. they can go into the third dimension. >> these new classrooms require active input from users. >> our correspondent is at the frankfurt book fair for us all week. how present our digital books at the fair this year? also, how much of a whole does digital technology have on the german market, would you say -- how much of a